Fillable cassette apparatus and method

ABSTRACT

A cassette is described including a housing, an inner reservoir located within the housing, a valve coupled to the inner reservoir and coupled to the housing, and a delivery conduit coupled to the inner reservoir and emerging from the delivery opening of the cassette. The cassette also includes a dispensing apparatus that defines a passage and has a first activating device that opens the valve of the cassette. The dispensing apparatus also has a second activating member capable of establishing fluid communication with a medicant container. A method of mixing a powdered drug and a liquid includes establishing fluid communication between the reservoir and the medicant container, dispensing at least a portion of the liquid into the medicant container, and transferring the mixed drug into the reservoir. A method of filling a cassette includes the steps of introducing the drug into the cassette, closing a first access port, evacuating the inner reservoir through a second access port, and introducing the drug to fill the cassette through the first access port.

FIELD OF THE INVENTION

The present invention is directed to a cassette for use with a drug pumpfor administering drugs and a method for administering drugs, and moreparticularly to a cassette and method that allows improved filling of acassette with a drug.

BACKGROUND OF THE INVENTION

Various ambulatory medical devices are known for treating and/ormonitoring patients at a remote site away from the caregiver's orclinician's office. One example of an ambulatory medical device is adrug delivery device, such as a drug pump, for providing periodic orcontinuous drug delivery to the patient when the patient is away fromthe caregiver's office. Ambulatory drug pumps are shown for example inU.S. Pat. Nos. 4,559,038, 5,531,697 and 5,695,473, the disclosures ofwhich are incorporated by reference.

Certain drugs rarely achieve their maximum therapeutic action throughconventional injection techniques. Many drugs reach their full potentialonly through precise delivery over an extended period of time. Withcontrolled drug infusion through a drug pump, the drug can be given at aprecise rate that will keep the drug concentration within thetherapeutic margin and out of the toxic range. Ambulatory drug pumps canprovide appropriate drug delivery to the patient at a controllable ratewhich does not require frequent medical attention and which allows thepatient to leave the hospital or caregiver's office.

Ambulatory drug pumps typically provide the patient with a drug or agentin liquid form, administering the liquid to the patient through aflexible conduit. Some drugs are sold in a powdered form. Examples ofdrugs on the market today that are sold in powder form includeampicillin, vancomycin hydrochloride, penicillin, nafcillin, andDesferal™ deferoxamine mesylate. Before powdered drugs are administered,they must be mixed with a liquid agent. When powdered drugs aredispensed at pharmacies, the pharmacist typically adds a liquid agent,such as a diluent, to the powdered drug at the pharmacy and then givesthe drug to the patient in a liquid form, for example, in a drug pumpcassette. The patient could then use the liquid drug with an ambulatorydrug pump. Examples of liquid agents that may be mixed with powdereddrugs are sterile water, dextrose and saline. These mixing steps requiresignificant pharmacist time and may cause a long wait for a patient whois filling the prescription. Current ambulatory drug pump cassettes donot conveniently allow the patient to perform the dilution orreconstitution of a powdered drug, so the patient must visit thepharmacist.

Certain types of drugs, such as ampicillin, have limited stability inliquid form. These drugs must be mixed with a liquid agent only a shortperiod of time before they are administered to the patient. Theshort-lived stability of these drugs necessitates frequent trips by thepatient to pick up the diluted drug or frequent deliveries of thediluted drug to the patient's location. In the alternative, somepatients are taught to mix drugs with a liquid agent at home. If knowndrug cassette configurations are used, this process may be awkward andcumbersome for the patient.

Another problem with filling cassettes for ambulatory drug pumps is theelimination of air from the reservoir within the cassette. Typically,cassettes are filled by injecting fluid through a delivery conduit thatis connected to the cassette reservoir. The delivery conduit is a tubethat connects the cassette to the patient for drug delivery. Pharmacistswill typically use a syringe or a pump to move the drug to beadministered into the cassette reservoir. After the cassettes arefilled, however, trapped air may be present in the cassette reservoir.Typically, the pharmacist will manually remove the trapped air from thecassette reservoir.

In one technique for manually removing trapped air, the cassette istapped until all the air bubbles have collected, and can be drawn outwith a syringe. This process is repeated until all of the air bubbleshave been removed. The method is time-consuming and labor-intensive forthe pharmacist.

There is a need for drug delivery systems and methods which address theabove-mentioned concerns, concerns about drugs that require dilutionand/or reconstitution before administration, and concerns about trappedair in the cassette reservoir.

SUMMARY OF THE INVENTION

The present invention concerns a drug pump cassette, including a housingthat defines a transfer opening and a delivery opening. The cassettealso includes an inner reservoir located within the housing. An accessdevice, or valve, is also provided on the cassette. The valve has afirst portion coupled to the inner reservoir at a transfer port and hasa second portion coupled to the housing at the transfer opening. Thecassette also includes a delivery conduit coupled to the inner reservoirat a delivery port, and emerging from the delivery opening of thecassette.

Preferably, the housing further includes a pressure plate supporting aportion of the delivery conduit. The pressure plate may be mounted to acontrol module of a pump.

The drug cassette may also include a dispensing apparatus. Thedispensing apparatus defines a passage and has a first activating deviceand a second activating device. The first activating device of thedispensing apparatus opens the valve of the cassette. The secondactivating device establishes fluid communication with a medicantcontainer. The second activating device may include a spike used topierce a septum of the medicant container, and an air vent to theatmosphere. The air vent may be provided with a filter.

In one method in accordance with the present invention, a liquid from acassette is mixed with a powdered drug in a medicant container and themixture is transferred back to the cassette. In an alternative method, aliquid from a container is mixed with a powdered drug in a cassettereservoir.

In a method for filling a cassette in accordance with the presentinvention, the inner reservoir of the cassette is evacuated through asecond access port before filling the inner reservoir with the drugthrough the first access port, thereby providing a filled cassette withminimized trapped air.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of a cassette for usewith a drug, a dispensing apparatus, and a medicant container.

FIG. 2 is a side view of the cassette of FIG. 1 where the components areconnected.

FIG. 3 is a side view of the connected cassette of FIG. 2, positioned sothat liquid within the cassette flows into the medicant container.

FIG. 4 is a side view of the connected cassette of FIG. 2 positioned sothat the drug in the medicant container flows back into the inner fluidreservoir of the cassette.

FIG. 5A is a side view of a luer-activated valve that may be used withthe cassette of FIG. 1.

FIG. 5B is a cross-sectional side view of the luer-activated valve ofFIG. 5A.

FIG. 6A is a front view of a first embodiment of a dispensing apparatusfor use with the present invention.

FIG. 6B is a side view of the dispensing apparatus of FIG. 6A.

FIG. 6C is a cross-sectional side view of the dispensing apparatus ofFIG. 6A.

FIG. 7 is a cross-sectional side view of a first portion of a secondembodiment of a dispensing apparatus of the present invention.

FIG. 8A is a front view of a second portion of the second embodiment ofthe dispensing apparatus of the present invention.

FIG. 8B is a side view of the second portion of the dispensing apparatusof FIG. 8A.

FIG. 8C is a cross-sectional side view of the second portion of thedispensing apparatus of FIG. 8A.

FIG. 9 is a side view of an alternative embodiment of the cassette ofthe present invention where the components are connected in which aninner reservoir contains a powdered drug and a medicant containercontains diluent liquid.

FIG. 10 is a side view of an alternative embodiment of a cassette foruse when mixing a drug or when using a method of the present inventionto fill the cassette while minimizing trapped air.

FIG. 11 is a perspective view of a drug pump control module.

FIG. 12 is a side view of the cassette of the present invention during amixing step.

FIG. 13 is a plan view of a cassette filling system of the presentinvention for minimizing trapped air in the cassette.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is applicable to a variety of systems andarrangements which are used to mix drugs before administration or tofill a cassette while minimizing trapped air before administration. Theinvention is advantageous in environments where a drug requires dilutionor reconstitution immediately before administration. A cassette isdescribed herein that allows a person, such as a patient, to easily mixa powdered drug with a liquid for administration with an ambulatory drugpump. The cassette of the present invention further enables the fillingof the cassette so that trapped air is minimized.

The cassette of the present invention includes an access mechanism thatallows a user to empty at least a portion of liquid contents of thecassette into a medicant container to mix and/or dilute the drug in thecontainer. The access mechanism then allows the user to transfer themixed together contents of the container to the cassette for use withthe drug pump. Alternatively, the access mechanism allows a user to addliquid to a powdered drug in the cassette. The access mechanism furtherpermits evacuation of an inner reservoir of the cassette so that trappedair in the inner reservoir and a delivery conduit can be reduced beforefilling with a liquid drug.

Referring now to FIGS. 1-12, a system 20 including a cassette 100, adispensing apparatus 102, and a medicant container 104 is shownaccording to one embodiment of the present invention. The cassette 100is designed for use with a drug pump (or control module) 164 as shown inFIG. 11. A pressure plate 106 of the cassette 100 mounts to the controlmodule 164 with two hooks 166 and an anchor 168, illustrated in FIG. 1.The two hooks 166 engage two pins 188. A latch 189 within the controlmodule engages the anchor 168. The cassette 100 further includes aninner reservoir 108, such as a flexible polymeric bag. Duringadministration of a liquid drug to a patient, the inner fluid reservoir108 will contain the liquid drug. The inner fluid reservoir includes twoopenings: a delivery port 110 and a transfer port 112, illustrated inFIG. 2.

The two ports 110, 112 of the inner reservoir 108 each communicate withopenings in a housing 114 of the cassette 100. The housing 114 defines adelivery opening 116 and a transfer opening 118. At the delivery port110 of the inner reservoir 108, the inner reservoir 108 is connected toa delivery conduit 120, such as a compressible polymeric tube thatemerges from the delivery opening 116 of the housing 114. The deliveryconduit 120 is supported by the pressure plate 106 of the cassette 100.The portion of the delivery conduit that is supported on the pressureplate 106 is the pump portion 122 of the delivery conduit 120. In theillustrated embodiment, the pump portion 122 may be larger in size thanthe remainder of the delivery conduit 120. When the cassette 100 ismounted to the control module 164, a pumping mechanism 172 (FIG. 11) ofthe control module 164 will act on the pump portion 122 to draw theliquid drug out of the inner reservoir 108 and move it along thedelivery conduit 120. The delivery conduit 120 is connected to a patientfor drug delivery. A luer fitting 109 or another type of connector and acap 111 may be provided at the end of the delivery conduit 120.

The cassette 100 also includes an access mechanism for allowingselective access to the interior of the inner reservoir 108. Onepreferred access mechanism includes a valve 124 capable of establishingfluid communication with the inner reservoir 108 in order to allowmixing with the contents of another container, such as the medicantcontainer 104. A dispensing apparatus 102 links the valve 124 of thecassette 100 with the medicant container 104. The valve 124 of theillustrated preferred embodiment includes a first portion 126 that isoperatively coupled to the inner fluid reservoir 108 at port 112. Thevalve 124 further includes a second portion 128 that is attached to thehousing 114 of the cassette 100 at transfer opening 118. The valve 124is capable of establishing fluid communication with the dispensingapparatus 102 when activated by the dispensing apparatus 102. The valve124 may be, for example, a luer-activated valve having a stopping member152 that can be depressed by a luer fitting to open a passage 154, asillustrated in FIGS. 5A and 5B. A biasing member 162 holds the stoppingmember 152 into engagement with the interior neck portion of the valve124. For use with such a luer-activated valve, the first activatingmember 130 of the dispensing apparatus 102 may be a luer fitting thatdepresses the stopping member 152. Many luer-activated valves arecommercially available that may vary from the valve shown in FIGS. 5Aand 5B, but could be used with the present invention.

Dilution of a drug, where the concentration of an active material isreduced, may easily be practiced using the present invention. Thepresent invention is useful where two drug components must be mixedprior to administration to a patient using a cassette. Possible drugmixtures that could be carried out with the present invention includecombining two liquids, or a solid and a liquid.

In use, the cassette 100 is attached to the dispensing member 102, andfluid communication is established between the dispensing member 102 andthe medicant container 104. In a preferred embodiment, the cassette 100will initially contain a liquid diluent 107 to be mixed with a powdereddrug. Examples of diluents include sterile water, saline, and dextrose.The cassette 100 may also initially contain another type of liquid agentfor mixing with a powdered drug.

In the embodiment of FIG. 1, the medicant container 104 initiallycontains a powdered drug 105 to be administered to a patient. Thedispensing apparatus 102 has a second activating member 132 forestablishing fluid communication with the medicant container 104. Themedicant container 104 may be a vial with a sealed, pierceable septum158. In this case, the second activating member is a spike 134 thatpierces the septum 158 and provides a passageway to the valve 124. Asdiscussed above, the dispensing apparatus also has a first activatingmember that is designed to open the valve 124, such as a luer fitting ifvalve 124 is a luer-activated valve.

In the embodiment illustrated in FIG. 1, the dispensing apparatus 102includes two parts, a vented dispensing pin 138 and a male-to-male lueradapter 140. However, a one piece dispersing apparatus 200 could be usedin place of the two piece dispensing apparatus 102. The one piecedispensing apparatus is illustrated in FIGS. 6A-6C and is discussedfurther below.

The two piece dispensing apparatus 102 is illustrated in FIG. 1. Theventing dispensing pin 138 includes the second activating member, orspike, 134, as shown in FIGS. 8A-8C. The male-to-male luer adapter 140includes the first activating member, a luer 136 for activating thevalve 124 as shown in FIG. 7. The vented dispensing pin 138 includes aluer lock that attaches to the opposite end of the male-to-male lueradapter 140, providing a passage for fluid communication.

The dispensing apparatus 102 may be provided with an air vent 142 tomore easily enable the flow of liquid between the cassette and themedicant container 104 by permitting displaced air or other gas toescape and allowing air to enter the connected cassette assembly,specifically the medicant container 104. The air vent 142 is constructedaccording to known methods for permitting the flow of gas, butpreventing the flow of liquid. For example, the air vent 142 may includea hydrophobic membrane that is penetrable by gases but not by fluids.Vented dispensing pin 138 and male-to-male luer adapter 140 arecommercially available as separate components. One example of adispensing pin 138 that could be used as a portion of the dispensingapparatus 102 is the DP-1000 Mini-Spike® dispensing pin assembly,manufactured by Burron OEM, a division of B. Braun Medical, Inc.

Referring now to FIG. 6A and FIG. 8A, the preferred air vents 142 and208 are similarly constructed. In the preferred embodiment, the liquiddoes not typically flow out of the air vent during filling or mixing,because the fluid tends to flow down the path of least resistance,therefore through the center passageway of dispensing pin. Anotherfactor which prevents the air vent of the present invention from leakingfluid is the capillary action of the small tip of the spike tip. Thisspike tip and its small passage discourages flow toward the ventopening. In addition, a half-shield structure 149 or 209 at the vent 142or 208 blocks some fluid flow out of the vent 142 or 208.

One example of a male-to-male luer adapter 140 that could be used aspart of the dispensing apparatus 102 is the male/male luer lockconnector, Model No. B1000200, manufactured by Burron OEM, a division ofB. Braun Medical, Inc. The male-to-male luer adapter may be constructedof polycarbonate ABS, polypropylene or other similar material and isshown in FIG. 7 in detail. The adapter 140 defines a passage 190. Theluer fitting 136 of the adapter 140 depresses the stopping member 152 ofthe valve 124 when the adapter 140 is connected to the valve 124. Asecond luer fitting 137 may also be included on the adapter 140. A cap144 may be used to protect the valve 124 before and after the mixingprocess and maintain aseptic conditions.

In an alternative embodiment, a dispensing apparatus 200 could be madeof only one piece as shown in FIGS. 6A-6C, having both a firstactivating member 202 and a second activating member 204 on the samebody connected in a permanent manner. In this embodiment there are fewercomponents for a user to connect.

The one-piece dispensing apparatus 200 may include a luer fitting as thefirst activating member 202. The first activating member 202 is designedto establish fluid communication with the valve 124. The firstactivating member 202, or luer, may also include threads along the wall205, for receiving and securing the luer-activated valve or other typeof valve. The threads would be similar to those illustrated in FIG. 7near the activating members 136 and 137. A second activating member 204may be a spike to pierce the septum of the medicant vial. The one-piecedispensing apparatus 200 also defines a passage 206 through its length.An air vent 208 may also be provided on the one-piece dispensingapparatus 200.

A spike guard 146 may be provided to protect users from the sharp spikethat may serve as the second activating member. Another optional featureof the dispensing apparatus 102 or 200 is an air inlet filter, not shownin the drawings. Such a filter may be useful to prevent particulatesfrom blocking the air vent of the dispensing apparatus 102 and tomaintain aseptic conditions. The filter may be separate from or combinedwith a hydrophobic membrane.

FIG. 10 illustrates an alternate cassette 300 having an outer surfacewith a recessed portion 302. A valve 304 is situated at the recessedportion of the cassette, reducing the likelihood that the valve or thevalve connection to a container will be bumped or damaged duringhandling. The valve at the transfer port can be located in manydifferent locations on the housing of the cassette in addition to thepositions illustrated in FIG. 1 and in FIG. 10. For example, the valvemay be located near the pressure plate 106. Alternatively, the valvecould be recessed into the cassette housing in many ways. Any valvelocation that permits fluid communication with the inner reservoir 108is within the scope of the present invention.

In one method of the present invention, the cassette 100 is provided tothe patient filled with a liquid such as a diluent liquid. The flexibleconduit 120 is closed using a clamp 160, for example, that pinches theflexible conduit 120. The patient may then remove the cap 144 from thevalve 124 on the cassette. The dispensing apparatus 102 or 200 iscoupled to the second portion 128 of the valve 124. The spike guard 146is removed from the spike 134. The second activating member 132 or 204is then used to pierce the septum 158, allowing a passage to be open tothe cassette.

After the cassette 100, the dispensing apparatus 102 or 200, and themedicant container 104 are connected in fluid communication, the systemis positioned with the cassette 100 on top, so that at least some of theliquid within the cassette 100 will flow into the medicant container104, as shown in FIG. 3. by arrow 148. The liquid is thereby mixed withthe powdered drug within the medicant container. The positioning of thesystem is then reversed so the medicant container 104 is on top, causingthe mixed liquid drug within the medicant container 104 to flow throughthe dispensing apparatus 102 or 200 into the cassette 100 as indicatedby arrow 150 in FIG. 4. The system may be tipped back and forth, asdesired, to ensure complete mixing. Using this method, a user may easilyand quickly reconstitute a powdered drug with a liquid at a locationremote from a caregiver's office.

The present invention has been described thus far by way of examplewhere the powdered drug is initially stored in the medicant container104, and a liquid initially is stored in the cassette 100. However, asshown in FIG. 9, it is also possible to provide a cassette 180 initiallycontaining the powdered drug. The cassette 180 is constructed in asimilar manner as the cassette 100, noted above. In this case, amedicant container 182 would contain a liquid, as shown in FIG. 9. Thepowdered drug would be mixed by connecting a dispensing apparatus 186with the valve 124 and the medicant container 182 in a similar manner asnoted above. The system would first be positioned with the container 182on top, allowing the liquid to flow into the inner reservoir 183 asindicated by the arrow 184. A mechanism for allowing the fluid to flowinto the cassette is desirable with this type of arrangement. Forexample, an air vent may be provided on the connection between themedicant container and the cassette. A syringe could also be attached tothe delivery tube to draw fluid from the medicant container into thecassette. A flexible medicant container could be used that could besqueezed to force fluid into the cassette. The dispensing apparatus 186may then be disconnected from the cassette 180, and the cassette may beshaken to mix the powdered drug with the liquid.

The pumping mechanism 172 may be utilized in the method of the presentinvention to ensure that the reconstituted drug is thoroughly mixed, asillustrated in FIG. 12. The delivery conduit 120 may be connected usinga luer fitting 210 to the valve 124. If the delivery conduit 120 is thenacted upon by the pumping pads 172, the reconstituted drug 212 will becirculated within a closed system defined by the delivery conduit 120and the inner reservoir 108. The control module 164 may be programmed toperform this mixing function for a predetermined amount of time. Theamount of time for which mixing is performed in this manner may dependon the type of drug that is being reconstituted and its ability todissolve within the diluent.

In another method of the present invention, the cassette 100 is filledwith a liquid drug for administration to a patient and the transfer port118 is utilized during the filling process to prevent air from beingtrapped in the inner reservoir 108 or delivery conduit 120. One sourceof trapped air is residual air that is in the inner reservoir 108 beforeit is filled. In the method of the present invention, this trapped airmay be removed by attaching a syringe or other vacuum source to a secondopening in the cassette, such as the transfer port. According to theinvention, a small amount, or a first amount, of the drug is introducedinto the cassette 100. The first amount of drug may be introduced to theinner reservoir of the cassette through the delivery conduit. Enoughdrug is introduced so that the delivery conduit is full, pushing all airthat previously was in the delivery conduit into the inner reservoir.

The introduction of the first amount of drug into the cassette can takeplace in many different ways. For example, as illustrated in FIG. 13 apharmacist may have a bulk dispensing pump 220 that is designed to pumpthe drug from, for example, a bulk supply reservoir container 222, intothe delivery conduit 120. A conduit 223 may be coupled to an opening onthe bulk reservoir 222, pass through the dispensing pump 220, and thenconnect to the connector 109 on the delivery conduit 120. The bulkdispensing pump 220 acts with a pumping action that is the reverse ofthe pumping action used when delivering drug from the inner reservoir toa patient. Further, many devices other than a bulk dispensing pump maybe used to introduce the first amount of drug to the cassette, includinga syringe, a pressurized supply or another pumping mechanism.

Once the delivery conduit 120 is filled with the first amount of drug,the delivery conduit 120 is clamped between the cassette and the drugsupply using clamp 224. At this point, the delivery conduit 120 betweenthe drug supply and the clamp 224 is filled with the drug and containsminimal, if any, trapped air. Then, a syringe 226 or vacuum sourceattached to the transfer port may be activated. The syringe 226 orvacuum source may alternately be attached before the introduction of thedrug into the delivery conduit 120, if the tube 228 leading to thesyringe 226 is clamped during introduction of the first amount, using aclamp 230. After the syringe or other vacuum source has evacuated theinner reservoir 108 through the transfer port 112, or second accessport, the inner reservoir 108 and delivery conduit 120 up to the clamp224 will be mostly devoid of gas and the first amount of drug. The valveat the transfer port 112 is then closed, or the clamp 230 is placed onthe tube that leads away from the transfer port 112.

Next, a second amount of the drug is introduced into the cassettethrough the first access port 110. Preferably, the second amount of thedrug is introduced into the inner reservoir 108 of the cassette 100 viathe delivery conduit 120. The second amount of drug enters the evacuatedinner reservoir 108 and air is therefore not trapped inside the innerreservoir 108. Preferably, the second amount of drug fills the innerreservoir 108 with the amount of drug necessary for providing thecassette to the patient.

The system and method for filling and minimizing entrapped air has thusfar been described for use with a cassette 100 where a delivery conduit120 is attached to the drug supply and the valve 124 at the transferport 118 is attached to a syringe or vacuum source. However, it is alsopossible to utilize the method of the present invention where the vacuumsource is attached to the delivery conduit 120 and a drug supply isattached to the valve 124 at the transfer port 118. The steps discussedabove would similarly be carried out in this scenario. One considerationwhen utilizing this embodiment is that most luer-activated valves, andother types of valves, open when a spring-loaded plunger is depressed.It is possible, therefore, that the luer-activated valve may be openedby the pressure differential caused when the vacuum source is attachedto the delivery conduit of the cassette. In this scenario, theluer-activated valve, or other valve used at the transfer port, will beconfigured to require more force to open the valve than is applied bythe vacuum source.

A tamper-resistant cap, such as cap 144, may be supplied for the valve.The cap may be placed on the transfer port by a pharmacist or careprovider after filling the cassette in order to offer additionalsecurity for the cassette. Tamper-resistant caps and other securityfeatures are especially important in the area of pain control. Manylocking mechanisms to secure the cap 144 are well-known in the art, andmay be used with the present invention.

The various embodiments described above are provided by way ofillustration only and should not be construed to limit the invention.Those skilled in the art will readily recognize various modificationsand changes which may be made to the present invention without strictlyfollowing the exemplary embodiments and applications illustrated anddescribed herein, and without departing from the true spirit and scopeof the present invention which is set forth in the following claims.

What is claimed is:
 1. A method of mixing a drug for administration in a cassette, comprising: providing a cassette including an outer housing, an inner reservoir structure within the outer housing, and a delivery conduit connectable to a patient, wherein the inner reservoir contains a liquid; establishing fluid communication through a fluid transfer connection separate from the delivery conduit between the reservoir of the cassette and a medicant container containing a drug; dispensing at least a portion of the liquid from the cassette into the medicant container to reconstitute the drug; transferring the reconstituted drug into the reservoir; and disconnecting the fluid transfer connection between the reservoir of the cassette and the medicant container.
 2. The method of claim 1, further comprising the step of providing a dispensing apparatus, and the step of establishing fluid communication further comprising establishing fluid communication between the dispensing apparatus and the cassette, and between the dispensing apparatus and the medicant container.
 3. The method of claim 1, wherein the dispensing step includes positioning the cassette above the medicant container.
 4. The method of claim 1, wherein the transferring step includes positioning the medicant container above the cassette.
 5. A method of mixing a drug for administration in a cassette, comprising of: providing a cassette including an outer housing, an inner reservoir structure within the outer housing, and a delivery conduit connectable to a patient, wherein the inner reservoir contains a powdered drug; establishing fluid communication through a connection separate from the delivery conduit between the inner reservoir of the cassette and a medicant container containing a liquid; dispensing the liquid from the medicant container to be mixed with the drug; and disconnecting the fluid transfer connection between the inner reservoir of the cassette and the medicant container.
 6. A method of filling a cassette with a drug for administration using a drug pump, comprising: providing a cassette including an inner reservoir structure in fluid communication with a first and second access port; evacuating the inner reservoir through the second access port; closing the second access port; and introducing the drug into the inner reservoir through the first access port.
 7. The method of claim 6, further comprising the step of introducing an initial amount of the drug into the cassette before evacuating the inner reservoir.
 8. The method of claim 6, wherein the cassette further includes a delivery conduit coupled to the first access port, and the step of introducing an initial amount of drug into the cassette comprises introducing the initial amount of drug into the delivery conduit.
 9. The method of claim 8, further comprising the step of closing the delivery conduit before evacuating the inner reservoir.
 10. The method of claim 6, further comprising the step of closing the second access port before introducing the drug through the first access port.
 11. The method of claim 6, wherein the cassette further includes a delivery conduit coupled to the second access port, the step of evacuating the inner reservoir comprising evacuating the inner reservoir through the delivery conduit.
 12. The method of claim 6, wherein the step of introducing comprises pumping the drug into the inner reservoir.
 13. The method of claim 6, wherein introducing the drug comprises filling the inner reservoir.
 14. A method of mixing a drug for administration in a cassette, comprising: providing a cassette including an outer housing, an inner reservoir containing a liquid, and a delivery conduit connectable to a patient; establishing fluid communication through a fluid transfer connection separate from the delivery conduit between the reservoir of the cassette and a medicant container containing a drug; dispensing at least a portion of the liquid from the cassette into the medicant container to reconstitute the drug; transferring the reconstituted drug into the cassette; connecting the delivery conduit to the fluid transfer connection so the inner reservoir and delivery conduit define a closed system; and activating a pump mechanism on a portion of the delivery conduit to circulate the reconstituted drug within the closed system of the inner reservoir, whereby the reconstituted drug is further mixed. 